Metal-Metal Terahertz Quantum Cascade Laser with Hybrid Mode Section

Fobbe, T, Nong, H, Schott, R et al. (11 more authors) (2015) Metal-Metal Terahertz Quantum Cascade Laser with Hybrid Mode Section. In: Infrared, Millimeter, and Terahertz waves (IRMMW-THz), 2015 40th International Conference. IRMMW 2015, 40th International Conference on Infrared, Millimeter, and Terahertz Waves, 23-28 Aug 2015, Hong Kong. IEEE . ISBN 978-1-4799-8272-1

Abstract

A hybrid mode section is integrated into the end of the metal-metal (MM) waveguide of a terahertz (THz) frequency quantum cascade laser (QCL) by removing sub-wavelength portions of the top metal layer. This allows a hybrid mode to penetrate into the air, which reduces the effective index of the mode and improves the out-coupling performance at the facet. The transmission of the processed metal-metal hybrid section (MMHS) waveguide is further increased by ensuring its length fulfills the criterion for constructive interference. These simple modifications to a 2.5 THz MM QCL waveguide result in a significant increase in the output emission power. In addition, simulations show that further improvements in out-coupling efficiency can be achieved for lower frequencies with effective refractive indices close to the geometric mean of the indices of the MM waveguide and air.

Metadata

Authors/Creators:

Fobbe, T
Nong, H
Schott, R
Pal, S
Markmann, S
Hekmat, N
Zhu, J
Han, Y
Li, L
Dean, P
Linfield, EH
Davies, AG
Wieck, AD
Jukam, N

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